The Ka band is currently being deployed for high-speed satellite communications. It is characterized by a very high frequency, leading to difficulties in technological development, a very large separation of the emission frequencies Tx, about 20 GHz, and the reception frequencies Rx, about 30 GHz, and a large usable bandwidth in the order of 2 GHz. Many companies are developing antenna systems compatible with mobile applications, either ground-based or aeronautical.
The use of satellite dishes in communication systems is not adapted for mobiles because their height is excessive, incurring restrictions on displacement, inability to be used when these systems become outsized, etc. Additionally, in the field of high-speed satellite communications, the standardized environment is important. The power density emitted off-axis is regulated in order to avoid the scrambling of other satellites. This forces the antenna to have a pattern with low sidelobes or array lobes.
Most of the solutions developed by the prior art are imperfect and generally exhibit rises in the sidelobes in certain directions. These solutions are based on dense arrays of sources, but the very high emission frequency in the Ka band of 30 GHz imposes compromises in terms of source density. One of the solutions offered is based on a quincunx array, which is easier to construct but which exhibits wide array lobes.
In the prior art known to the Applicant, the antennas used operate in the Ku band. In the Ku band, two types of solution are used to produce such antennas.
A first type is the type A, as described in patent application US 2011/0267250 in which the dense arrays of elementary sources are of horn or slit type. The second type of solution is the type B in which the arrays are based on sources of large size, for example according to the patent U.S. Pat. No. 6,563,473. To avoid the presence of array lobes, the distance between elementary sources must be shorter than the wavelength, for example 1 cm in the Ka band. This condition is adequate but not necessary. It is also generally necessary for the power density over the whole surface of the antenna aperture to obey precise mathematical laws, and it is for example possible to use a uniform law which will not give rise to array lobes.
Solutions of type A are complicated in terms of application and expensive in the Ka band because:                the array pitch of 1 cm leaves very little space for performing the operations,        the number of sources is very high (1408) for a typical antenna of 22 cm by 64 cm,        the separation of 10 GHz between the TX and RX frequencies as well as the bandwidth of 2 GHz impose solutions (relative band of 30%).        
Type B solutions are easier to produce because they include fewer sources. As the separation between sources is greater than the wavelength, the presence of array lobes is generally permitted.
The U.S. Pat. No. 6,563,476 describes an antenna system working in the Ku band, the frequency band of which is twice as low, in which the separation between sources is irregular, for two or more than two sources.
The patent application US 2011/0267250 presents a solution that consists in bringing the sources closer together by asymmetrically shortening the reflectors. This solution works with two sources.
The prior art known to the Applicant does not describe any antenna with weak lobes having more than two sources.